Compilare: user.cpp: In function ‘int main()’: user.cpp:112:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<h[i].size();++j) ^ user.cpp:115:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j==h[i].size()-1 || b[h[i][j+1]]<b[h[i][j]]) ^ user.cpp:127:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=j=1,t=0;t<optim.size();++t) ^ user.cpp:165:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0,printf("%d\n",sol.size());i<sol.size();++i) ^ user.cpp:34:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compunere.in","r",stdin); ^ user.cpp:35:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compunere.out","w",stdout); ^ user.cpp:37:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&M); ^ user.cpp:41:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i]); ^ user.cpp:47:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&b[i]); ^